1. Field of the Invention
This invention relates to a control system for gathering bar materials such as steel bars in a steel bar production line in an iron and steel plant.
2. Description of the Prior Art
In the production of steel bars, steel bars are normally produced in the steps shown in FIG. 1. Namely, the raw materials are in the form of rectangular prisms or so-called billets having a sectional size of 155 mm.times.155 mm and a length of 12 m. These billets are transferred to a billet charging conveyor 1 by means of a crane apparatus. Then, the billets are successively charged into a heating furnace 2 piece by piece and heated up to a specified temperature at which the billets are discharged out of the heating furnace. In this heating furnace, the billets are transferred from the charging end to the discharging end while being heated therein.
When the billets are heated up to a specified temperature, they are discharged out of the heating furnace to a rolling mill 3 where they are rolled to a specified size. When the billets are rolled, they are cut by a hot shear 4 to a suitable length for them to be accommodated in a cooling bed 5. The bar materials which are placed on the cooling bed are referred to as divided bars and are cooled by air on the cooling bed. A group of several divided bars are then together cut to a specified length by a cold shear 6. The sheared materials are then transferred to a classifying pocket 8 by a classifying bed 7 and are gathered in classifying pocket 8 as a group comprising a specified number of bars. Each group is transferred as a unit to a binding machine 9 where they are bound and then transported to a product storage yard by means of a crane or the like by way of a conveyor 10.
At the time of cold shearing said divided bars, it has been normal practice for an operator to determine how many divided bars are required to be cut in accordance with the actual number of divided bars available and the required number of bars ordered. As shown in FIG. 2, the cold shear has cutting blades of different sections depending on the size of the divided bars to be cut. Additionally, the maximum number of bars to be cut at one time is limited by the capacity of the cold shear. FIG. 2 shows the groove patterns at the cutting face of the cold shear. The pattern 1 in FIG. 2 is for bars of the minimum size, and divided bars corresponding to 17 grooves may be cut by this. On the other hand, although the pattern 2 which is for bars of the maximum size has 5 grooves, the maximum number of bars which can be cut with it is limited to three.